1. Field of the Invention
The present invention relates to the use of Kaempferia galanga extract to photostabilize a topical sunscreen composition and synergistically enhance the UV absorbancy of a sunscreen composition. More particularly, the present invention relates to a sunscreen composition having a sunscreen active, particularly dibenzoylmethane and/or its derivatives, and an extract of Kaempferia galanga, particularly from the root thereof. The present invention also relates to a method of photostabilizing a sunscreen active in the topical sunscreen composition. The present invention further relates to a method of synergistically enhancing the UV absorbancy of a topical sunscreen composition having at least one sunscreen active.
2. Description of the Prior Art
Commercial sunscreen compositions commonly include at least one sunscreen active. To specifically protect against UV-A radiation, a UV-A sunscreen, such as a dibenzoylmethane derivative (e.g. butylmethoxydibenzoylmethane also known as avobenzone) is used to provide protection from UV-A radiation.
A common problem associated with some sunscreen compositions is a tendency of sunscreen actives, including dibenzoylmethane and/or derivatives thereof, to photodegrade over time from exposure to UV (ultraviolet) light. This results in a reduction of the UV absorbance of the composition, particularly UV-A absorbance, and, thus, a diminution in sunscreen protection for the user during extended exposure to sunlight.
U.S. Pat. No. 5,952,391 relates to sunscreen compositions having dibenzoylmethane sunscreen actives. The compositions have flavone or flavanone derivatives to stabilize the dibenzoylmethane actives.
An extract of Kaempferia galanga is disclosed in Naturally Occurring Isoamyl p-Methoxycinnamate, Cosmetics and Toiletries magazine, vol. 112, pp. 74–77, January 1997, which is incorporated herein by reference thereto. Topical compositions having the extract are disclosed in Japanese Application Nos. 8157346A2, 61291515A2, S61-291515 and 9030948A2. The extract has been disclosed as useful as a sunscreen, anti-inflammatory agent, skin lightening agent and food ingredient.
It would be desirable to have a sunscreen composition that is photostable and affords the claimed sunscreen protection for an extended period of time. It would be further desirable to have a photostable sunscreen composition that has a dibenzoylmethane and/or derivative thereof (hereafter collectively “dibenzoylmethane”). It would be still further desirable to have a photostable sunscreen composition that affords an enhanced degree of sunscreen protection.